Modern digital oscilloscopes generally provide the capability to generate a time domain waveform of a given input signal. Some instruments may include the capability to generate a spectrum or frequency domain display of the input signal. A digital processor within the oscilloscope generally performs a frequency domain transform on the input signal to generate the frequency domain display. Existing devices lack an effective way to simultaneous display time domain and frequency domain waveforms and the relationship between the two waveforms. Accordingly, there exists a need for a test and measurement instrument including such simultaneous time domain and frequency domain display capabilities.